wg48temp9 - 16-12-2020 at 07:42
I found a half full old bottle of blackcurrant and apple cordial at the back of a kitchen cupboard. It had what looked like a fungus growing on part
of the liquid surface. So I poured it down the sink and flushed it away. But I was surprised when I noticed a strong-ish methyl methacrylate smell. Of
cause it may not have been that.
Do some fungi or yeasts produce a metabolite of methyl methacrylate or a compound that smells similar?
Boffis - 16-12-2020 at 11:46
I have had liquid malt extract do the same, only my fungus cocktail smelled of ethyl acetate, acetone and such things. On looking into it there are
bacterial fermentation products of glucose that generate n-butanol and acetone, ethanol, acetic acid etc so there is a lot of scope here 
.
unionised - 16-12-2020 at 11:53
Just about anything is possible with microbes.
https://en.wikipedia.org/wiki/Acetone%E2%80%93butanol%E2%80%...